Reduce page cache size on Mac
https://bugs.webkit.org/show_bug.cgi?id=111795

Rubber stamped by Geoff Garen

5 entries is unnecessarily large; research show 3 should suffice.
On a low memory warning we should clear this completely.

Source/WebCore: 

* platform/mac/MemoryPressureHandlerMac.mm:
(WebCore::MemoryPressureHandler::releaseMemory):
    - clear the page cache completely

Source/WebKit2: 

* Shared/CacheModel.cpp:
(WebKit::calculateCacheSizes):
    - reduce maximum to 3.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145154 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Unreviewed gardening.

* platform/chromium-linux/compositing/overflow/composited-scrolling-paint-phases-expected.txt: Added.
* platform/chromium-linux/platform/chromium/virtual/gpu/compositedscrolling/overflow/composited-scrolling-paint-phases-expected.txt: Added.
* platform/chromium-linux/platform/chromium/virtual/softwarecompositing/overflow/composited-scrolling-paint-phases-expected.txt: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145155 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Need API to draw custom overhang area
https://bugs.webkit.org/show_bug.cgi?id=111679
-and corresponding-
<rdar://problem/13291415>

Reviewed by Simon Fraser.

Source/WebCore: 

This will allow clients to put custom images into the top or bottom overhang area.

New FrameView API takes a bool indicating whether the client wants a top/bottom 
overhang layer. If the bool is true, the overhang layer will be returned. 
* WebCore.exp.in:
* page/FrameView.cpp:
(WebCore::FrameView::setWantsLayerForTopOverHangArea):
(WebCore::FrameView::setWantsLayerForBottomOverHangArea):
* page/FrameView.h:
(FrameView):

Keep member variables for the top and bottom overhang layers. Create them if 
necessary, and update them if the root layer changes.
* rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::updateRootLayerPosition):
(WebCore::RenderLayerCompositor::updateLayerForTopOverhangArea):
(WebCore::RenderLayerCompositor::updateLayerForBottomOverhangArea):
(WebCore::RenderLayerCompositor::reportMemoryUsage):
* rendering/RenderLayerCompositor.h:
(RenderLayerCompositor):

Source/WebKit2: 

The new API is WKBundlePageSetTopOverhangImage() and 
WKBundlePageSetBottomOverhangImage(). When the API is called, WebPage will get 
GraphicsLayers for the appropriate area from FrameView, and then set the image as 
the contents of the layer.

* WebProcess/InjectedBundle/API/c/WKBundlePage.cpp:
(WKBundlePageSetTopOverhangImage):
(WKBundlePageSetBottomOverhangImage):
* WebProcess/InjectedBundle/API/c/WKBundlePage.h:
* WebProcess/WebPage/WebPage.h:
(WebPage):
* WebProcess/WebPage/mac/WebPageMac.mm:
(WebKit::WebPage::setTopOverhangImage):
(WebKit):
(WebKit::WebPage::setBottomOverhangImage):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145156 268f45cc-cd09-0410-ab3c-d52691b4dbfc